I think they should keep the limit on regeneration, and do an episode where the doctor actualy dies, but then the timelords (who return before then) grant him an extra 13 incarnations like they did with the master in the timewar as their version of a medal of valour. Then that's the problem solved until doctor number 26 decides to leave..............

Problem with that is, that the Doctor wouldn't be in good graces at all with the Time Lords right now, considering he destroyed/time locked them twice

I think the best route to follow is to simply have the atmosphere of believing he will die (Maybe even plant a phony rumor of cancellation to give it credibility and a surprise), and then have him regenerate and be shocked by it, and then explain it. Hiring A new actor for the Doctor, is an impossible secret to keep, but, it would be really, really cool, if they could make us believe it really will be the end, and then have him regenerate and the Showrunner could go "Pysche"

Like a false cancellation rumour will work. It'll never work as soon as the press get a hold of it the BBC will be for a lot of flak.

DW is a massive show, a huge hit for the BBC, it's not unheard of the press to publish pictures of episodes being filmed. DW isn't some show that only pulls in a few million viewers, it can pull in over 7m+ with an audiance share of ~40%.

Never mind the cancelling the show part, simply planting a false rumour will likely get the BBC into trouble.

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On the continent of wild endeavour in the mountains of solace and solitude there stood the citadel of the time lords, the oldest and most mighty race in the universe looking down on the galaxies below sworn never to interfere only to watch.